Alistair,

Just be aware that as :
a) Water has a different visosity than air;
b) the Reynolds No. (non-dimensional number controlling viscous flow
behaviour)
 of a model in water bears no relation to that of a full sized vehicle in
air -

------- you are unlikley to come to any useful conclusions using your flume
tunnel.

However, tufting your van and using mirrors or a camera to observe the flow
might
be more worthwhile- but your conclusions from what you see - again - might
not.

Regards,

Clive
'88 Syncro Transporter
----- Original Message -----
From: "Alistair Bell" <albell@UVIC.CA>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Thursday, August 22, 2002 6:37 PM
Subject: Re: Custom Scoop Update - Should you care!

> Regarding scoops laminar flow and slipstreams etc
>
> I have to say form the limited experience I have had this summer building
> and testing a research flume (sort of like a air tunnel but using water
> instead of air), fluid dynamics is (for those of us limited in math and
with
> no access to  super computers) very much an empirical practice.
>
> While you can look at a model/set up and make some predictions as how the
> fluid will flow around/through it, often it will be very surprising to see
> the flow in reality.
>
> Time restraints will probably preclude this but I want to build my Revell
> Vanagon model and stick it in the flume to watch the flow around it!
>
> Years ago the list was discussing flow around the van etc, all kinds of
> crazy and neat ideas surfaced. I had the idea of sticking little yarn
> "tell-tales" (tell-tails?) all over the van then driving at various speeds
> in still air and see (via chase van) just how the air flowed over the
> shoebox.
>
> Alistair
>
>
>
> on 8/22/02 10:11 AM, 80 Westy Pokey wrote:
>
> > OK, I "Googled" and  stole this from:
> > http://www.aviation-history.com/theory/lam-flow.htm&e=653
> > Then applied the principals to our Vans: